Vermont Seeks to Raise Awareness About Emerald Ash Borer Threat

Forester Courtney Haynes, left, examines a young white ash tree as she leads a small group, including Kevin Eaton of East Corinth, Vt., and Penny Andrew of Corinth, Vt., for an informational walk about the non-native emerald ash borer in the Corinth town forest on April 27, 2014. Guided nature walks highlighting the threat of the invasive, tree-killing pest took place across Vermont as part of Ash Tree Awareness week. (Valley News - Will Parson) Purchase photo reprints »

Forester Courtney Haynes holds a sample piece of ash tree showing the S-shaped tunnels, called galleries, formed by the non-native emerald ash borer during a guided walk in the Corinth, Vt., town forest on April 27, 2014. When the insect infests an ash tree, the galleries girdle and kill branches and trees by disrupting the flow of nutrients. (Valley News - Will Parson) Purchase photo reprints »

The group was one of a handful that met around the state this weekend to kick off Vermont’s first Ash Tree Awareness week, intended to honor the state’s 160 million native ash trees and to raise awareness of the threat they face from the nonnative insect, the emerald ash borer.

“Good grief,” said Corinth resident Penny Andrew during the walk at the prospect of losing a wide swath of the area’s woodlands. “It’ll kill all our trees.”

Ash trees tend to grow vertically straight making their wood valuable for furniture, said Courtney Haynes, a forester with the Corinth-based land management consultant Redstart, Inc., who led the walk.

Ash tree wood is also flexible, which is an ideal material for baseball bats, bows, basket-making and hockey sticks, she said.

The United States Department of Agriculture Forest Service estimates the country is home to 8 billion ash trees, valued at more than $280 billion.

The adult emerald ash borer eat a tree’s leaves and lay eggs in the bark. The eggs hatch and larvae emerge to tunnel and create S-shaped tracks or “galleries” — hence the “borer” in the insect’s name — as they feed throughout the winter, cutting off the tree’s access to water and nutrients, eventually killing them.

Vermonters may be familiar with the purple traps the USDA and Vermont Agency of Agriculture have placed in ash trees, perhaps most visibly hanging along the interstates, although Haynes said it’s not usually officials who spot the insect first.

Haynes passed around two vials, one containing a shiny green adult emerald ash borer and one with a less flashy tan larva.

“People on the ground are actually doing the sighting,” she said.

The emerald ash borer is thought to have stowed away in packing materials of a cargo ship or airplane from China before its discovery in southern Michigan in 2002.

It didn’t take long for devastation to follow: That state no longer has any living adult ash trees, said Haynes.

“As far as we know, it’s not in Vermont yet,” Haynes comforted her audience.

But that could soon change as the emerald ash borer is on Vermont’s doorstep. The insect has been spotted in two Canadian provinces and 21 states, including Vermont’s neighbors New Hampshire, Massachusetts, New York and Quebec.

The first step in identifying emerald ash borers is to recognize the ash trees to which they are drawn, Haynes told the walkers. The tree’s hardwood, leafless this time of year, grows branches symmetrically. The bark is a grayish-brown color and ridges in older trees grow to form diamond shapes.

Symptoms that an ash borer attack is in progress might include significant woodpecker activity because the bird likes to eat the larvae — which turns the tree a blond color, Haynes said.

Once an infestation has begun it is too late to save the tree, said Haynes.

So slowing the spread of the insect is really the only thing loggers, landowners, and cities and towns with ash-lined streets can do.

The infestation in New Hampshire, spotted just last spring, seems at present to be isolated to Merrimack County, near Concord, said Haynes. Officials there have placed a quarantine on wood leaving the region.

To prevent the spread of pests such as the emerald ash borer officials discourage residents and visitors from transporting firewood for distances farther than 50 miles, said Haynes.

Single trees may be protected through preemptive insecticide application, said Haynes, though she did not recommend that tactic until the insect has been spotted nearby.

Some states have introduced wasp parasites from the emerald ash borer’s native China, but Haynes struck a note of caution on that front saying that introducing another nonnative species could have unforeseen consequences.

Brad Wheeler, a Corinth resident, asked whether landowners should cut down all of their ash trees in preparation for the insect’s attack.

Haynes said that landowners who are harvesting timber now might want to include their mature ash trees because “the chances of them being around in 10 years is low.”

Nora Doyle-Burr can be reached at ndoyleburr@vnews.com or 603-727-3213.